论文标题
在物理点上呈茶的连续二十二个nnlo价pdf
Continuum-extrapolated NNLO Valence PDF of Pion at the Physical Point
论文作者
论文摘要
我们介绍了使用近代到接头领导顺序（NNLO）扰动QCD匹配的暂停Parton分布函数（PDF）的晶格QCD计算。我们的计算基于2+1风味的三个量规集合，高度改进的交错夸克和威尔逊 - 克洛斯夸克夸克，对应于Pion Mass $m_π= 140 $ 〜MEV，在晶格间隔$ a = 0.076 $ a = 0.076 $ 〜fm和$m_π= 300 $ a = 300 $ a = 0.04 $ a = 0.04 $ a = 0.04 $ a = 0.04 $ a = 0.04 $ 〜FM。这使我们能够首次呈现在物理点的茶的nnlo Valence pdf的连续性晶格QCD结果。将领先的扭转扩展用于重新归一化组不变式（RGI）的比率（rgi）比nnlo wilson系数的双局部型矩阵元素，我们提取$ 2^{\ mathrm {nd}} $，$ 4^{\ 4^{\ Mathrm {thth}} $ and $ 6^$ and}我们使用深神经网络（DNN）以及使用混合式cheme重新归一化的动量空间矩阵元素从真实空间RGI比率中重建了NNLO PDF的Bjorken- $ x $依赖性。我们所有的结果都与Xfitter和JAM协作进行的实验数据的全球拟合结果吻合。
We present lattice QCD calculations of valence parton distribution function (PDF) of pion employing next-to-next-leading-order (NNLO) perturbative QCD matching. Our calculations are based on three gauge ensembles of 2+1 flavor highly improved staggered quarks and Wilson--Clover valance quarks, corresponding to pion mass $m_π=140$~MeV at a lattice spacing $a=0.076$~fm and $m_π=300$~MeV at $a=0.04, 0.06$~fm. This enables us to present, for the first time, continuum-extrapolated lattice QCD results for NNLO valence PDF of the pion at the physical point. Applying leading-twist expansion for renormalization group invariant (RGI) ratios of bi-local pion matrix elements with NNLO Wilson coefficients we extract $2^{\mathrm{nd}}$, $4^{\mathrm{th}}$ and $6^{\mathrm{th}}$ Mellin moments of the PDF. We reconstruct the Bjorken-$x$ dependence of the NNLO PDF from real-space RGI ratios using a deep neural network (DNN) as well as from momentum-space matrix elements renormalized using a hybrid-scheme. All our results are in broad agreement with the results of global fits to the experimental data carried out by the xFitter and JAM collaborations.
